Verfahren zur Herstellung von geformten Gebilden aus regenerierter Cellulose

Regenerated cellulose filaments, films and like products are produced by extruding viscose containing a salt of an N-substituted dithiocarbamic acid (said salt being soluble to the extent of at least 0.05 per cent in 6 per cent aqueous sodium hydroxide solution) into an acid coagulating bath containing 1-15 and preferably 3-10 per cent of zinc sulphate. Filaments thus produced may be stretched, preferably in a secondary hot bath. The salt should contain no radical of more than 18 carbon atoms and is preferably a mono- or diN-substituted dithiocarbamate containing no radical of more than 10 carbon atoms and having the nitrogen atom attached to aliphatic carbon. The salt may be sodium cyclohexyl, amyl, butyl, monoethanol, hexymethylene bis, methyl, benzyl, ethylene bis, 1,3-cyclohexane bis, dibutyl, dimethyl, dioctyl or lauryl dithiocarbamate, potassium pentamethylene dithiocarbamate, lithium cyclohexyl dithiocarbamate, sodium hexamethylene bis (isobutyl dithiocarbamate), sodium ethylene-bis (methyl dithiocarbamate), sodium 1.4-cyclohexane-bis (ethyl dithiocarbamate), or sodium xylylene-bis (dithiocarbamate). The salt may also be an ammonium or an amine salt. The concentration of the dithiocarbamate in the viscose should preferably be up to about 0.75 and more particularly up to 0.5 per cent, a generally useful range being 0.05 to 0.3 per cent by weight of the viscose. In addition to the dithiocarbamate there may be present in the viscose the etheric modifiers described in Specification 741,728 and/or polyethylene glycol of molecular weight about 300-1000. Sodium sulphate is usually present in the spinning bath but is not essential. The bath may also contain additional salts of divalent metals such as manganese sulphate or nickel sulphate and particularly ferrous sulphate. Preferably the spinning bath contains, in addition to 1-15 per cent of zinc sulphate, 4-12 per cent of sulphuric acid and 13-25 per cent of sodium sulphate, optionally with 1 to 5 per cent ferrous sulphate. The filaments may be stretched 20-30 per cent for textile yarns or 80-100 per cent for high tenacity yarns in a secondary bath consisting of water, 1-3 per cent sulphuric acid or a four-fold dilution of the coagulating bath, preferably at 50-100 DEG C. In an example an unripened viscose of salt index 16.0 containing 5 per cent of cellulose, 6.5 per cent of sodium hydroxide and 0.15 per cent of sodium cyclohexyl dithiocarbamate is spun at 62 DEG C. into a coagulating bath containing in a